Screen and Projector Distance Calculator
Calculate centered viewing distance at an entered horizontal angle and projector lens-distance bounds from screen size, aspect ratio and throw ratios.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Derive the active image rectangle, solve viewing distance from half-angle geometry and multiply image width by entered throw-ratio endpoints.
Width=diagonal×a/√(a²+b²); viewing distance=width/[2tan(angle/2)]; throw distance=width×throw ratio
Worked example
A 100-inch 16:9 image is about 2.213802 m wide. Entered throw ratios of 1.2–1.6 give approximately 2.656563–3.542084 m lens distance.
Assumptions and input details
The viewing angle is an editable scenario rather than an ergonomic recommendation. Centered viewer, flat active image and simple distance/width throw convention are assumed. Projector lens shift, offset, zoom limits, borders, obstructions and product-specific installation requirements are outside this geometry; verify the actual projector documentation.
References: Epson: projection distance depends on image size, aspect and zoom
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
Enter a screen diagonal and pixel resolution to calculate active width, height, aspect ratio, pixel density and pitch, with a dimensioned screen diagram.
Calculate horizontal, vertical and diagonal field angles and scene coverage from sensor dimensions, focal length and subject-plane distance.
Calculate a centered crop or a whole-image resize inside a target pixel box. Inspect retained area, edge trims, output dimensions and upscaling.
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